Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. However, the mechanistic insights of interaction between plasmon energy and organic molecules is still under debate. Herein, we proposed a comprehensive study of the plasmon-assisted reaction mechanism using unsymmetric iodonium salts (ISs) as an organic probe. The experimental and theoretical analysis allow to exclude the possible thermal effect or hot electron transfer. We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C-I bond with the formation of electron-rich radical species, which cannot be explained by the hot electron excitation or thermal effects. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of dissociative excited state according to quantum-chemical modeling, which provide a novel opportunities to the fine control of reactivity using plasmon energy.

In this paper, the utilization of plasmon‐induced cleavage of CI bond in the structure of iodonium salt followed by grafting of organic radicals to Au surface is proposed. The plasmon is excited by the coupling of Au‐covered optical fiber with the laser light source, with wavelength corresponding to the plasmon absorption band, and immersion of fiber in the solution of iodonium salt. Grafting procedure is monitored through the shift of surface plasmon resonanse (SPR) position during the laser light transmission. Further verifications are performed using the surface enhanced Raman spectroscopy (SERS) and scanning electron microscopy and energy‐dispersive X‐ray spectroscopy methods. Only in the case of coincidence of coupled laser emission and initial SPR absorption band wavelengths efficient activation of diaryliodonium salt (IS) is observed. With the aim to introduce hydrophobic and repellent surface properties the di‐[3,5‐bis(trifluoromethyl)phenyl]iodonium tetrafluoroborate salt is used. Surface functionality is further tested using the wettability and antifouling test. Proposed method for the first time utilizes the plasmonic phenomenon as an effective tool for initiating the iodonium salt heterophase reaction and can be considered as extremely effective approach in the case of surface activation, in terms of energy and materials harvesting.

<p>Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. Herein, we propose a comprehensive investigation of plasmon-triggered decomposition of iodonium salts containing various substituents (ISs). We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C–I bond with the formation of electron-rich radical species. Such unprecedented C–I cleavage brings the possibility of selective surface modification using ISs. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of dissociative excited state ac-cording to quantum-chemical modeling.</p>

The chiral recognition of organic compounds is of vital importance in the field of pharmacology and medicine. Unfortunately, the common analytical routes used in this field are significantly restricted by time spent and equipment demands. In this work, we propose an unprecedented alternative, aimed at enantiomer discrimination and estimation of their concentrations in an uncomplicated and instantaneous manner. The proposed approach is based on the creation of an optical fiber probe with two pronounced plasmonic bands attributed to gold and silver. The gold or silver surfaces were grafted with moieties, able to enunciating entrap chiral amines from solution, resulting in a wavelength shift corresponding to each plasmonic metal. As a model compound of chiral amine, we chose the DOPA, also taking in mind its high medical relevancy. For chiral detection, the optical fiber probe was simply immersed in an analytical solution of DOPA, and the selective shift of gold or silver plasmon bands was observed in the reflected light depending on DOPA chirality. The observed shifts depend on the concentration of DOPA enantiomers. In the case of a racemic mixture, the shifts of both plasmonic bands emerge, making possible the simultaneous determination of enantiomer concentrations and their ratio. The analytical cycle takes several minutes and requires very simple laboratory equipment.

Covalent organic frameworks (COFs) are an emerging class of crystalline networks that are covalently built from organic components and featured by merits of low density, well-defined pore aperture, large surface area, inherent porosity, facilely tailored functionality, and ordered channel structure. Among other applications, COF compounds can be utilized for CO2 detection. It Is known that the preparation of COFs compounds is commonly associated with hard experimental conditions (high pressure, inert atmosphere, and high temperature). In this work, we suggest an alternative method of COFs under normal pressure and temperature. The experimental concept implements the surface-assisted COF growth. The created surface-immobilized COF structures were subsequently used for measurement of CO2 presence.